The present invention relates to a door apparatus for opening and closing side doors of a train.
A mechanism for opening and closing a door of a train is an essential part for the safety of passengers on the train. Once the door of the train is closed, the door should not be opened accidentally regardless of moving or stationary. Further, the doors must always be held closed with a specific force to prevent rain or wind from entering, and to suppress vibrations. However, when an emergency such as a power failure happens to stop the train and the passengers need to evacuate from the train, it must be possible for a passenger to manually open the door relatively easily. Thus, a train door apparatus must be able to work very reliably. The inventor has already developed a train door apparatus that meets these requirements and applied for a patent (see Japanese Patent Publication (KOKAI) No. 2000-142392).
FIGS. 14 to 17 show a train door apparatus according to Japanese Patent Publication (KOKAI) No. 2000-142392. This apparatus is briefly described below. FIG. 14 is a front view showing an entire train door apparatus. FIG. 15 is an enlarged view of an essential part of the train door apparatus. In FIGS. 14 and 15, two doors 1 and 2 are movably suspended from and supported by a door rail 3 horizontally mounted along a side of a train. The two doors move in opposite directions (left and right in the figure) to open or close the train doorways. The door 1, shown at left in the figure, is driven by a linear motor 5 as an actuator connected to a moving member 4 of the door 1.
As shown in FIG. 15, a moving unit 5a of the linear motor 5 engages the moving member 4 to be able to slide for a predetermined distance xe2x80x98xxe2x80x99 in an opening or closing direction (to the right or left in the figure). A compression spring 6 is interposed between the moving unit 5a and the moving member 4, as shown in the figure. Thus, the linear motor 5 is connected to the door 1 so that the door can move by the distance xe2x80x98xxe2x80x99 in the opening direction thereof.
The right door 2 moves in cooperation with the door 1 via a direction conversion mechanism 7. As shown in FIG. 15, the direction conversion mechanism 7 is composed of a lower rack 9 connected to the moving member 4 of the door 1 via a connection rod 8, an upper rack 11 connected to the moving member 4 of the door 2 via a connection plate 10, and a pinion 12 that simultaneously engages these racks 9 and 11. The lower rack 9 and the upper rack 11 are guided to be able to slide within a unit case 7a fixed to the train in the opening or closing direction, and the pinion 12 is supported by a shaft fixed to the unit case 7a. The opening or closing movement of the door 1 driven by the linear motor 5 is transferred to the door 2 by changing the direction by the direction conversion mechanism 7.
FIGS. 16 and 17 are detailed views showing a locking mechanism 13 (in FIG. 14) attached to the direction conversion mechanism 7 and pushing/pulling attachments (members) 14 and 15 for locking and unlocking the locking mechanism 13. FIG. 16 shows a locked state, while FIG. 17 shows an unlocked state. In FIGS. 16 and 17, the pushing attachment 14 and the pulling attachment 15 are attached to a tip of the moving unit of the actuator 5.
The pushing attachment 14 has a rod-like shape and one end horizontally fixed to the actuator 5. The pulling attachment 15 with a key-shaped tip is placed on a top surface of the pushing attachment 14, and has one end joined to the actuator 5 by a pin to rotate and move along the vertical axis. The pulling attachment 15 is urged upward by a compression spring 16 interposed between the pulling attachment 15 and the pushing attachment 14. A pin 17 with a head is screwed into the pulling attachment 15 while loosely passing through the pushing attachment 14, and limits an upward rotational range of the pulling attachment. A guide fixture 18 contacts a top surface of the pulling attachment 15 and is attached to a tip of a fixed portion of the linear motor 5 to stop the pulling attachment from rotating upwardly.
The locking mechanism 13 has a slider 19 guided to be able to slide in the directions in which the doors 1 and 2 move; a back spring 20 composed of a compression spring to urge the slider 19 toward the door 2; a latch 21 guided to be able to slide vertically; and a locking spring 22 composed of a tension spring to urge the latch 21 downward. The slider 19 has a cam surface 19a disposed on a top surface thereof having an oblique stage surface, and an engaging protruding portion 19b provided at a tip thereof. Although not shown in detail, the latch 21 is composed of a vertical latch rod 24 guided to be able to move up or down inside a guide cylinder 23 fixed to a unit case 7a, and a frame 25 integrated with the latch rod 24. A roller 26 is rotatably attached to the frame 25 to contact the cam surface 19a of the slider 19. The locking spring 22 for urging the latch 21 downward is provided between the frame 25 and the unit case 6a. As described later, the latch 21 advances or retracts in concert with the opening and closing operations of the doors.
In the door apparatus described above, FIG. 16 shows a state in which the doors 1 and 2 are closed and locked. In this state, a tip of the latch rod 24 advances into an engaging hole 27 in the upper rack 11, which constitutes an engaging portion of the direction conversion mechanism 7, thereby locking the sliding motion of the upper rack 11. Thus, the doors 1 and 2, linked to the upper rack 11, will not move.
In this state, the pushing attachment 14 abuts against the engaging protruding portion 19b of the slider 19, and the key-shaped portion of the pulling attachment 15 engages the engaging protruding portion 19b. When a signal is sent to open the door, the moving unit 5a of the linear motor 5 moves to the left. With the door 1 staying at its closed position, the moving unit 5a initially moves to the left by a predetermined distance xe2x80x98xxe2x80x99 while pushing the compression spring 6. The pulling attachment 15 pulls the slider 19 via the engaging protruding portion 19b. At this time, the pulling attachment 15 tries to move upwardly, but it can not open, as it is pressed by the guide attachment 18.
When the slider 19 is pulled and moved to the left, the roller 26 is pushed onto an upper surface of the cam surface 19a via the inclined surface thereof as shown in FIG. 17. Thus, the latch 21 is lifted to withdraw the latch rod 24 from the engaging hole 27 to unlock the upper rack 11, thereby unlocking the doors 1 and 2. Once the moving unit 5a moves by the distance xe2x80x98xxe2x80x99, the guide attachment 18 stops pushing the pulling attachment 15. As a result, the pulling attachment 15 rotates upward by the compression spring 16 and is released from the engaging protruding portion 19b of the slider 19. Although the pulling attachment 15 is released, the slider 19 remains at its forward position due to a spring force of the back spring 20, thereby keeping the roller 26 pushed up.
Subsequently, the moving unit 5a moves the door 1 leftward to its predetermined open position. Correspondingly, the door 2 linked to the door 1 via the direction conversion mechanism 7 moves to the right to open the doors 1 and 2. Thereafter, a signal is sent to move the door 1 to the right, and the door 1 moves to its closed position, shown in FIG. 16. Then, the moving unit 5a pushes the slider 19 via the pushing attachment 14. As a result, the roller 26 falls from the upper surface of the cam surface 19a, and the latch rod 24 advances through the engaging hole 27 in the upper rack 11 to lock the doors again. When the doors need to be opened in an emergency, a handle 28, shown in FIG. 14, is rotated by 90 degree to pull up the latch 21 via a wire 29, thereby forcibly unlocking the doors.
In a state where the doors are closed, and the latch is engaged to lock the doors, if a hand or a cloth of a passenger is caught between the doors, the locked doors can not be manually opened. Thus, there is a safety problem associated with the train door apparatus described above.
It is thus an object of the present invention to improve the safety of a train door apparatus in an emergency when the train door apparatus has locked the door while in a closed state.
Further objects and advantages will be apparent from the following description of the invention.
To attain the above objects, the present invention provides a door apparatus. The door apparatus keeps a door in a semi-locked state rather than a fully locked state, even when the doors are closed, so that the door can be opened manually in a certain extent for a while after the train has left a station. For this purpose, in the present invention, a direction conversion mechanism transmits a movement of one door driven by an actuator to the other door in a converted direction. The direction conversion mechanism has a two-stage engagement portion with a latch. When the latch moves down to the first stage of the engagement portion, the doors become in a semi-locked state so that the door can be opened manually in a predetermined distance. When the latch moves further down to the second stage of the engagement portion, the door is completely locked. A stopper mechanism is provided to stop the latch during the operation. When the door is closed, the stopper mechanism stops the latch at the first stage of the engaging portion. Then, when the train reaches a specified speed or higher, the latch is released and moves through the engaging portion down to the second stage.
As a way for moving the latch in connection with the opening and closing operations of the doors, the actuator is connected to one of the doors to be able to move to open the door in a predetermined distance, as shown in Japanese Patent Application (KOKAI) No. 2000-142392. The apparatus is provided with the slider supported to be able to slide in a door moving direction and having a stage cam surface on a top surface; a back spring for urging the slider toward one of the doors; a roller connected to the latch and contacting the cam surface of the slider; a locking spring for urging the latch toward an engaging portion of the direction conversion mechanism; and pushing/pulling attachments (members) attached to the actuator.
When the doors are closed, the actuator pushes the slider via the pushing attachment. The roller is pushed down from an upper stage of the cam surface by the locking spring, and the latch advances into the engaging portion, thereby locking the doors in a closed state. When the doors are opened, the actuator moves in the predetermined distance in the opening direction to pull the slider via the pulling attachment. The roller is pushed onto the upper stage of the cam surface, thereby withdrawing the latch from the engaging portion to unlock the door.
As another means for moving the latch in connection with the opening and closing operations of the doors, the apparatus may be provided with a locking spring for urging the latch toward the engaging portion of the direction conversion mechanism and a solenoid for driving the latch against a force of the locking spring. In this case, to close the doors, the latch is moved into the engaging portion by the locking spring to lock the doors, whereas to open the doors, the solenoid moves the latch from the engaging portion to unlock the doors.
As yet another means for moving the latch in connection with the opening and closing operations of the doors, the apparatus may be provided with a solenoid for driving the latch to advance into the engaging portion of the direction conversion mechanism or retracts therefrom. In this case, to close the doors, the solenoid moves the latch to enter into the engaging portion to lock the doors, whereas to open the doors, the solenoid moves the latch to withdraw from the engaging portion to unlock the doors.
The stopper mechanism is constituted of a slide piece for abutting against the latch when the latch advances into the engaging hole and a solenoid for moving the slide piece into or out in a latch moving path.